The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Solenoid operated valves are known which provide control of a fluid such as pressurized air for use in operating additional equipment such as sorters, packaging machines, food processors, and the like. In order to retain the solenoid operated valve in a closed position, biasing members such as springs are known.
It is also known, for example, in U.S. Pat. No. 4,598,736 to Chorkey that an inlet pressure of the pressurized fluid can be balanced within the valve to reduce the force required by the solenoid assembly to move a valve member between closed and open positions. Known designs have several drawbacks however. The valve member is often assembled from several parts which increases the valve costs. Known designs also provide separate resilient valve elements which can be widely spaced from each other to provide a valve open and a valve closed seal. A total displacement or throw of the valve member is commonly not adjustable. Balancing the valve member to allow free sliding motion of the valve member often requires multiple flow passages, which also increases valve costs and complexity. In addition, common valve designs do not provide for axially adjusting the spacing between seating surfaces and therefore cannot adapt to control seating integrity as wear of the resilient seal material occurs. Common valves also lack the capability to prevent the system fluid from contacting the coil of the solenoid assembly. Moisture and dirt as contaminants in the fluid can therefore enter the solenoid assembly which can result in valve sticking, reduced valve power, or delayed operating times.